The purpose of the present invention is to provide a photopolymerizable composition which can act as a photopolymerization sensitizer that is active against light having a wavelength falling within a wavelength range of from 300 to 500 nm, and which has such a property that coloring of a cured product produced by polymerizing a photopolymerizable composition containing the photopolymerization sensitizer is less.
A photopolymerization sensitizer composition characterized by comprising a photopolymerization sensitizer containing an alkoxyanthracene compound represented by the formula (1) and a singlet oxygen quencher; and a photopolymerizable composition containing the photopolymerization sensitizer composition: in the formula (1), n represents an integer of 1 or 2; R represents a C1-12 alkyl group; and X represents a hydrogen atom or a C1-8 alkyl group.